The present invention is directed towards ball type trailer hitches and more particularly to a self-aligning hitch which will align and engage the ball by merely backing the towing vehicle into engagement with the tongue member of the trailer.
Self-aligning hitches have been available for the semi-truck type hitch for many years. However, the conventional ball and socket hitches utilized on pickup trucks and smaller trailers have not had self-aligning devices of any commercial significance.
In the U.S. Pat. to Collins No. 4,226,438 and the U.S. Pat. to Eichels No. 3,773,356, the broad concept of tapered sidewalls is taught. Neither of these patents provide a removable ramp means for supporting and lifting the tongue over the ball.
In the U.S. Pat. to Thompson No. 3,588,145, the general concept of a lifting ramp with tapered sidewalls for laterally aligning the hitch over the ball is taught in FIGS. 13 through 17, and 39 and 40.
Most commercial hitches have always utilized a ball and socket connection wherein the ball is mounted in an upstanding manner on the towing vehicle with the inverted socket on the tongue trailer. Trailers which have carried light tongue weights are not difficult to attach to the ball, since they can be easily lifted manually and guided over to engagement with the ball. However, trailers with higher tongue loads are very difficult to manually attach to a stationary towing vehicle, but rather require the towing vehicle to maneuver the ball precisely under the stationary inverted socket of the tongue and then lower the tongue into engagement with the ball through the use of a screw jacket or similar device. When an individual attempts this alignment process by himself, it becomes very difficult since he cannot see from the driver's seat the alignment of the tongue and ball. In the last-mentioned patent to Thompson, a somewhat similar device to the present invention is utilized wherein a ramp means having tapered sidewalls is provided to lift and guide the trailer tongue into position over the ball, whereupon further movement of the tongue releases a locking pin and allows the ramp to drop so that the socket of the tongue engages the ball.